The present invention relates to the field of curing epoxy resins.
Polyoxypropylenepolyamines react with epoxy resins at a rate which is unsatisfactorily slow for certain applications. In order to provide a rate of cure which is satisfactory for most uses an accelerator must be used with the polyoxypropylenepolyamines in order to speed the rate of cure.
Lee, Henry and Neville, Kris, Handbook of Epoxy Resins, McGraw-Hill Book Co., N.Y., 1967 p. 7-14, describes the use of N-(2-aminoethyl)piperazine as an epoxy curing agent and at page 11-18 describes the use of salicylic acid as an accelerator for urea-formaldehyde epoxy resin coatings. Bobby Leger's U.S. Pat. No. 3,462,393 (Aug. 18, 1969) teaches the use of polyoxyalkylenepolyamines as curing agents for a polyglycidyl ether of a phenolic compound.
U.S. Pat. No. 3,639,928 claims the use of a combination of N-(3-aminopropyl)piperazine and salicylic acid as an accelerator combination with polyoxyalkylenepolyamine for curing epoxy resins.